The present invention relates generally to the field of sanding devices and, more particularly, to an improved abrasive pad for polishing or sanding the inside of hollow objects.
A variety of mechanisms have been used in the past to sand the inside of hollow objects. Generally, these devices have consisted of a square pad made up solely of two strips of an abrasive sanding material which are folded at right angles over each other. The pad is designed to be attached to a mandrel, which spins the pad such that its four corners may be used to polish the inside of an object, such as a hollow cylinder.
However, these devices have a number of drawbacks. First, their formation is such that a good deal of the abrasive material is not used and is, therefore, wasted. Second, they are not designed to dissipate heat caused by frictional contact when in operation. Third, they do not lend themselves to efficient and cost-effective manufacturing. Fourth, they are limited in the type of abrasive materials with which they may be used. Fifth, they often vibrate when in use because of imprecise centering of the mandrel with the pad.
Hence, it would be useful to provide an abrasive pad which is more cost effective to manufacture, can be made with a wide variety of abrasive materials, and results in improved operations.
With parenthetical reference to the corresponding parts, portions or surfaces of the disclosed embodiment, merely for purposes of illustration and not by way of limitation, the present invention provides an improved abrasive pad (15) comprising an inner core (16) having an outer surface (19), a strip of abrasive material (18), the strip of abrasive material wrapped around the outer surface of the inner core, and a central throughbore (20) extending through the material and the inner core and adapted for engagement with a torque-producing device. The outer surface of the abrasive pad may comprise a top surface (21), a bottom surface (22), a front surface (23), a rear surface (24), a right surface (25), and a left surface (26), and the abrasive strip may be wrapped over the right surface, the bottom surface, the left surface, and the top surface to form a first layer (28) of abrasive material. The abrasive strip may be wrapped around the inner core at least twice to form at least a second layer (29) of abrasive material. The abrasive material may be sandpaper.
The throughbore may be threaded (35) for engagement with a mandrel. The throughbore may further comprise a grommet (36) holding the strip of material around the inner core. The inner core may be generally rectangular and further comprise at least one chamfer surface (38).
Accordingly, the general object of the present invention is to provide an improved abrasive pad which may be used to polish or sand the inside of hollow objects.
Another object is to provide an improved abrasive pad which increases airflow so as to decrease heat associated with its use.
Another object is to provide an improved abrasive pad which employs an inner core around which an abrasive strip is tightly wound.
Another object is to provide an improved abrasive pad with a core which assists in automating the manufacturing of the pad.
Another object is to provide an improved abrasive pad in which the abrasive material is tightly wrapped.
Another object is to provide an improved abrasive pad which may be manufactured so as to conserve abrasive materials.
Another object is to provide an improved abrasive pad which may be composed of a number of types of abrasive materials.
Another object is to provide an improved abrasive pad which allows for the use of more expansive and better abrasive wraps.
Another object is to provide an improved abrasive pad which allows for more precise centering of the eyelet or throughbore.
Another object is to provide an improved abrasive pad which reduces vibrations when in use.
Another object is to provide an improved abrasive pad which dissipates heat when in use.